Floor sander



May 3L 1938. N, N, @KUN Z@ FLOOR SANDER Filed Feb. l5, V195:5 4SheebS-heet 1 ay 31, w36. N. N. @KUN www FLOOR SANDER Filed Feb. 13,1933 4 Sheets-Sheet 2 may 31 1933#v I N. N. OKUN 2,]l1l,

` FLOOR SANDER y Filed Feb- 13. 1955 4 sheets-sheet 3 ATTORNE Skms.NNOKUN ,Hmm

FLOOR SANDER Fileg Feb. 13, 1953 4 Sheets-Sheet 4 ATTORNEY- Patented May31, 1938 UNITED STATES ausg Pari-.1r

FFICE FLOOR SANDER Application February 13, 1933, Serial No. 656,392

14 Claims.

The present invention is a oor sanding machine and an object thereof isto provide an improved sanding machine characterized in that the framethereof pivotally carries intermediate wheels which serve as iulcrummeans continuously held in contact with the surface to be treated bycontrollable resilient means. The invention has as a further object theprovision of a sanding machine in which conveniently adjustable means isprovided for shifting the rear end of the frame to permit the latter tobodily tilt about the intermediate wheels. The invention has as afurther object the provision of a sanding machine having meansadjustable for setting the rear portion of the frame to permit thesurface treating member thereof to effect predetermined cuts on thesurface to be conditioned without resorting to manual tilting of themachine and without the need of or depending upon the skill of theoperator to manually hold the machine by its handle at certain degreesof inclination. Other objects, features and advantages of the inventionare in part obvious and in part hereinafter more fully pointed out andfor a clearer understanding of the principles underlying the scopethereof attention is directed to the accompanying drawings in Which:

Fig. l is a side view of the sanding machine according to my invention.

Figure 2 is a plan view taken along the line .2-2 of Figure 1.

Figure 3 is a rear view showing the handle cut off.

Figure 4 is a sectional side View on the line 4--4 of Figure 8 showingthe parts with the sanding drum lifted clear of the floor.

Figure 5 is a sectional View on the line 5 5 of Figure 1.

Figure 6 is a section on the line 6 6 of Figure 5.

Figure '7 is a view, partly in section, on the line l-l of Figure 8 on alarge scale, similar to Figure 1, but with certain parts broken away andshowing the drum making a deep cut.

Figure 8 is a View on the line 3 8 of Figure l, showing the parts in thesame position as in Figure 1.

Figure 9 is a sectional view of the adjusting mechanism shown in Figure3, the parts, however, being positioned as in Figure 8.

Figure 10 is a side view of certain of the parts when the machine isbeing pulled backward, the parts being in the position of Figure 8.

Figure l1 is a sectional view on the line lI-Il of Figure l.

Figure 12 is a section on the line |2-|2 of Figure 4.

Figures 13, 14 and 15 are drawings showing fragmentarily rasp-likecutting devices. adapted to replace the usual sand-paper.

The operator who is intending to sand or grind down a floor 2l), takeshold of the machine by the handle 2| and shifts the handpiece 22 awayfrom the handle 2| by pushing a lug 23, against the tension of a spring22a, out of a notch 24 in a guide quadrant thus shifting a connectingrod 26, pivotally attached at 2l to the handpiece 22, so that it thrustsdown a rear swivelled wheel 28, to effect cutting as described below.When shifted in the opposite direction it permits the operator to tiltthe frame or casing 29 of the sanding machine backward around centralwheels 30 so as to lift the sanding drum 3| away from the oor to theposition shown in Figure ll. The operator then wheels the machine toworking position.

To start cutting, the operator shifts the handpece 22 to the positionseen on the upper part of Figure 1 thus thrusting the swivelled or reartrailing wheel 28 downwardly with the result that the sanding drum 3|takes the position shown in Figure l in which the drum cuts into the oor2|] to make a reasonably shallow cut as illustrated in said Figure 1.

To cause the sanding drum 3| to elect this cutting, the drum, as bestseen in Figure 8, is covered with sand paper 32 lying on a resilientrubber mat vulcanized to the drum on its broad face plate 33. The faceplate 33 is supported by plates or arms 34 extending from hubs 35 toiianges 36 which fit closely the back of the face plate 33. The faceplate 33 is held to the flanges 36 by screws 3l threaded into the faceplates so that their countersunk hubs 38 lie iiush with the surface ofthe drum. The hubs 35 are held fast by set screws 39 to a transverseaxle i0 provided with ball races 4| and i2 at its ends, forming parts ofball-bearings 43 which also include races M mounted in the wall or sideplates 45 of the sander frame 29.

The ball-bearings 43 are adapted to hold the drum 3| against side motionbetween the walls 5, thus enabling the drum to run with its right handedge 53 just clear of the inside l|'| of the right hand side plate 45,with the result that the sandpaper 32 will sand a floor up to withinless than an inch of the outside oi" the right hand side plate 45. Toenable this to be done, the right hand ball-bearing 43 lies entirelywithin the plate 45 and the plate or arms 34 bend inwardly to the hub35. The left hand hub 35 may be identical with the right hand hub 35,but the ball-bearing 42 may be carried in a cup 48 extending through theleft hand wall plate 45, thus giving a firmer bearing for the balls 43to enable them to withstand the tension of the driving belt 49 whichpasses around a pulley 59, fast on the left hand end of the shaft 49,the belt 49 being driven by a pulley 5| on the shaft of a motor 52.

The motor 52 is shown as mounted nearly centrally on the top plate 53 ofthe sander body, on lugs 54 which extend outwardly from it, and areprovided with slots 55 through which pass bolts 55 which may be loosenedso that the motor is adjustable along the top 53 to vary the tension onthe belt 49.

The motor is a heavy part of the mechanism and is shown as mountednearly vertically over the intermediate wheels 38. In the form shown,

.the wheels 38 run within inwardly bent rearward extensions 51 and 58 ofthe right and left hand side plates 45 respectively. To cause the wheels38 to tend to guide the sanding machine straight forward and back theyare shown as independently mounted upon swinging or p-ivoted arms 59journalled to swing freely around a transverse shaft 69, the swingingarms 59 being provided with hubs 9| which ride between internalprojections 62 of the side plates 51 and 58 and collars 53 fast on thetransverse shaft 59. Each wheel 39 is shown as journalled in a shortstub shaft E4 projecting outwardly from its swinging arm 59.

The Wheels 39 are each shown normally held downward against the floor bya spring G5 bearing against an adjustable abutment 6E threaded into aninternal ear 61 projecting from the adjacent side plate. Each spring 55is shown as bearing against an abutment 68 on a presser rod 69journalled at 18 on the rock arm 59 and riding freelyup and down in acentral hollow of the thumb screw 1| which adjusts the abutment 66.

To prevent the springs 65 from over-throwing the wheels 30 each presserrod 69 is threaded at its upper end 12 and provided with lock nuts 13above the thumb screws 1| so that if the wheel 38 is pressed too far outby its spring the lock nuts 13 will be stopped by the thumb nut 1|. Thesprings 65 are not strong enough to carry the whole weight of thesanding machine, but carry a substantial fraction of its weight.

In order to enable thewheels 39 to accurately control the maximum out ofthe sanding drum 3|, they are provided with stops 15 and 16. The stop 15on the left hand side plate extension 58 may be formed as a lug cast onthat plate but at least one of the stops 15 and 16 is ordinarilyintended to be adjustable.

The right hand stop 16 is herein shown as the head 11 of a bolt 18threaded into a lug 19 on the right hand side plate extension 51 andlocked in position by a lock nut 80.

As a result of the foregoing structure, the operator can accurately knowin advance the depth of cut which will be produced by the sanding drum3| at any given position of the handle 22. When the wheels 39 are on anormal oor run their rock arms 59 are in contact with their stops 15 and16, but when the machine reaches a hollow in the floor either wheel 39which is not in actual contact with the floor is for the workman pushingthe sanding drum 3| across the floor.

In the form of the device herein shown, the side plate extensions 51 and58 are provided with openings 8| so that the thumb screws 1| and nuts 13are easily accessible. The wheels 39 run in cutaway portions 32 of theside plates so that the stop 15 is also easily accessible.

The connections by which the fingerpiece 22 pushes the rod 25 to movethe wheel 28 include a pivot 83 and a backward extension 84 of thesegment 25. The push rod 25 itself is provided with an upward extensionengaging the stem 86 of the rigerpiece 22 by the pivot 21.

When the fingerpiece 22 is pushed down the push rod 25 is thrust downand carries down (see Fig. 9) a rock arm 83 fast on a transverse rockshaft 89 which is journalled in two brackets 98 and 9|, projectinginwardly from an outside plate 92 which lies against and overlaps thesides of an opening 93 at the back 94 of the machine frame.

When the push rod 26 is depressed it rotates the shaft 89 therebyrotating a rock arm 94, also fast on the shaft, with the result that aspur gear 95 swings downwardly and carries downwardly a rack 98, formingpart of a slidable post or extension 91, which slides up and down in ahollow Vertical extension or sleeve 98 of the plate 92. To keep the postor shaft 91 from rotating in the hollow extension 98, the shaft 91 isprovided with a set screw 99 which rides up and down in an open slot |98at the back of the projection 98.

The trailing wheel 28 is swivelled on the shaft 91 by being journalledon a short axle i8! on a rearward extension |92 of a cup |93 providedwith upper and lower ball-bearings |94 and |95 so that bearings |94 and|85 rotate freely on suitable ball races |06 on the shaft 91.

To nearly balance the pressure of the wheel 28 against the ngerpiece 22there is provided a spring |01 (see Fig. 9) which bears against anabutment |08 on a thrust bar |09 pivoted at H0 to a rock arm fast on theshaft 89.

It will be observed that the plate 92 is held to the body 29 of themachine by four screws ||2 so that the structure which controls thecontrolling wheel 28 is easily removable, practically as a unit. Theplate 92 also carries an upper socket H3 in which the handle post H4 ismounted thus rendering the structure very simple to assemble.

The pressure on the spring |91 is easily adjusted by a finger screw H5threaded into a socket H4 also forming part of the plate 92, theopposite end H8 of the finger screw H5 forming an abutment for thespring while the thrust bar ||1 which carries the abutment |98 ridesloosely in an opening H8 in the stem of the nger screw I I5.

To withdraw the dirt and refuse from around the drum 3|, there isprovided a fan H9 having an outside pulley |29, both fast to a shaft|2I. The shaft I 2| is provided with suitable ball bearings |22 in aboss |23 forming part of a plate |24 so that the plate |24, beingslightly larger than the fan, may be held against the rearward sideextension 58 by screws 25 threaded into the side 53 through lugs |29 inthe plate. The fan and its mounting are therefore removable as a unit.

There is also provided a dust collecting funnel shown in Figures 8 and4, which has a forward curved end |21 and transverse closed top |28 Ciland bottom |29 which lie close to the surface of the sanding drum 3|, sothat when the fan is rotating it draws air through the opening formed bythe curved sides |21 and top |28 and bottom |29 through the constrictedportion |30 of the funnel and discharges it tangentially through achannel 3| into a bag |32.

The funnel |3| is held in place by front screws |33 near the front edge|21 andby rearward screws |34 threaded through the side 58 into a flange|35 which lies around the opening |35 through which the fan I9 isinserted.

The passageway |3| as is most clearly seen in Figure 4 up to the top 29of the machine, may be formed as an extension of the flange |35 whichforms a fan-housing and delivers the air into a pipe |39 having flanges|40 which hold it to the top 29 of the machine.

As has been heretofore mentioned, the motor is adjustable on the top ofthe machine to adjust the belt 49. To enable the belt |4| which drivesthe fan ||9 by the pulley |20 to be adjusted, there is provided a post|42 on the side 58 on which is pivoted a segment |43 carrying. on anextension |44, an idler pulley, |45 which bears against the belt |4|between the pulley |20 and the pulley |46. The idler pulley |45 may beadjusted by loosening a screw |41 which passes through a slot |48 in thesegment and then adjusting the segment to position the pulley to thedesired point and then tightening up the screw.

In order to guide refuse eifectively into the funnel |30, a front hood|50 is pivoted above the drum 3| at I5| somewhat behind the shaft 40, soas to overlie the front of the sides 45. The hood guides the refusesucked back by the air suction into the funnel |30 until it comes to theedge |28 and then the refuse is sucked down past the edge |28 because ashort transverse partition |53 just above and behind the edge |28 limitsthe area from which air is drawn.

The front of the hood |50 is shown as carrying a rubber buffer |55adapted to arrest the machine without damage when it strikes a wall.

The most satisfactory mat |55 is found to be a sheet of ne texturedsponge rubber, about an eighth of an inch thick, having continuous outerfaces and vulcanized to an outer thin canvas sheet.

For drawing the sand paper tight over this mat |55 two circular clampshave been found satisfactory each consisting of a knurled rod |51 (seeFigure 2) journalled at one shouldered smoothed end |58 in a socket |59in the end plate 34 at the very end of the drum, and journalled at theother smooth shouldered end 15| in an opening |52 extending through theopposite end plate 34 so that the rod may be turned by inserting atriangular key in a small triangular socket |54 in the end of the rod|51. Preferably the socket |59 for one rod |51 is at one side of thedrum and the socket |59 for the other rod |51 at the other side of thedrum, so the triangular sockets |64 are at opposite ends of the drum,but the rods are set at an angle to the axis of the drum.

The sand paper 32 is stretched around the mat |55 by carrying its ends|55 down through a diagonal slot |69 in the face plate 33 and thenbetween the rods |51, (shown on an enlarged scale in Figure 2) which forthis purpose are provided with at cutaway faces |08, and then turningthe rods by keys in their sockets |54. The sand paper is thus held outto its edges, or at least to the inside edge of the end plate 34, thusgiving uniform tension and ample grip.

The rods |51 may be locked by set screws |61, and if desired may bejournalled in brass or iron bushings (not shown). The frame ispreferably aluminum, but the bearing shaft |50, the outside plate 92,the ball bearings, and the bear ings on the plate 92 are preferably ofsteel or brass as the case may be, thus producing a machine light enoughto be carried easily and yet having no soft aluminum wearing parts.

The device has so far been described as a sanding machine, but it isWell adapted to be used for removing a surface by the aid of a rasp faceinstead of a sand paper face, on the drum 3|, thus working moreeffectively on rough surfaces. Such a cutting face is provided bystretching around the blanket or mat |55, a rasp face made by punchingup projecting points |69, fromthe back of a sheet of spring steel |10.

For one depth of cut the points project about a sixteenth of an inchfrom openings |1| an eighth of an inch wide in a sheet tenone-thousandths of an inch thick. The points, as clearly appears inFigure 13, are offset from each other along the axis of the drum so thatsuccessive points |60 cut to one side or the other of the center of thecut of the preceding points |59. Such a rasp face on a resilientmounting equal to the blanket or mat |56 provides a rasp cutting surfacefree from the objections found in using a rigidly mounted rasp face.

The-steel plate |10 is held in place by its two turned down smooth ends|12 which project into the opening between the rods |51, so that therods can be rotated to lock it down on its resilient backing mat |55.

For some purposes it is desirable to have a rasp face which need not becleaned fromclogging refuse or detritus. To attain this end the sheetsteel plate |10 may be provided with oppositely faced alternate rows ofteeth or points |30 and |13 as shown in Figure 15, with the result thatthe plate may be used to cut rst with the teeth |69 until clogged, thenremoved, and used to cut with the teeth |13, or vice versa, incidentlypartly or largely cleaning the clogged teeth when reversed.

The structure of Figure 15 simplifies the equipment which a workmanneeds to take to a new job, especially for use on 01d oors.

Having thus described certain embodiments of the invention what isclaimed is:

l. In a floor surfacing machine, the combination of, a frame having arotatable drum normally disposed above a surface to be conditioned,guide wheels continuously in rolling contact with said surface andswingably connected to intermediate parts of the sides of said frame,spring means for holding said guide wheels in contact with said surface,a rear trailing wheel continuously in rolling contact with said surfaceand a connection controlled from separate sources for controlling theelevation of the rear portion of said frame relative to said trailingwheel for bodily tilting said frame about said guide wheels to move saiddrum towards or away from said surface.

2. In a surfacing machine, the combination of, a frame having arotatable drum normally disposed above a surface to be conditioned, arear trailing Wheel continuously in rolling contact with said surface, aswingable arm carried by each side of said frame, a rotatable guideWheel sustained by each of said arms, adjustably controlled spring meansacting on said arms to hold a respective guide wheel in rolling contactwith said surface, stop means to limit retraction of said arms, and aconnection operatively associated with said frame and cooperating tobodily raise or lower the latter relative to said trailing wheel fortilting said frame bodily about said guide wheels and control thedisplacement of said drum respectively towards or away from saidsurface.

3. In a surfacing machine, the combination of, a frame having a drumnormally above a surface to be conditioned, yieldingly controlled andintermediately arranged spaced guide wheels operatively connected tosaid frame, a trailing wheel continuously in rolling contact with saidsurface, a post associated with said trailing wheel and comprising arack, a sleeve carried by said frame and slidably guiding said rack, asegment in mesh with said rack, and adjustable means for actuating saidsegment and rack to elevate the rear portion of said frame to bodilytilt the latter about said guide wheels concomitantly lowering said drumtowards and against said surface.

4. In a surfacing machine, the combination of, a frame having a drumnormally above the elevation of a surface to be conditioned, yieldablycontrolled spaced guide wheels continuously in rolling contact with saidsurface, a trailer wheel having a swivel connection, a sleeve carried bysaid frame, said connection comprising a rack guided in said sleeve, agear in mesh with said rack, and actuating means for displacing saidgear to shift said sleeve relative to said rack to bodily lift or lowerthe rear portion of said frame and tilt the latter about said guidewheels to lower or raise said drum towards and against said surface oraway from the latter respectively.y

5. The surfacing machine according to claim 4 in which a rotatablemanipulator is carried by said frame and said actuating means comprisesa spring controlled by said manipulator for variably adjusting thepressure imparted by said drum against said surface.

6. The surfacing machine according to claim 4 characterized in that saidframe includes a rearwardly disposed inclined handle, a guide roddisposed alongside of said handle and operatively connected to saidactuating means, and lockable lever means for controlling said rod tobodily tilt said frame about said guide wheels whereby the rear portionof the said frame is raised or lowered relative to sai-d rack fordisplacing said drum towards and against said surface or away therefromrespectively.

'7, In a oor surfacing machine, the combination of, a frame having afo-rwardlydisposed rotatable surfacing drum and a rearwardly disposedsleeve, a trailing wheel having means to support the rear end of saidframe and comprising an upstanding member slidably guiding said sleeve,spring controlled arms swingably connected to the sides of said frameand each carrying a guide wheel intermediately. 'disposed relative toends of said frame, a connection associated with said member forelevating the rear end of said frame to pivot the latter about saidguide wheels to differentially control the imparted pressure by saiddrum against a surface to be treated, and a rotatable member extendingrearwardly of said frame to actuate said connection.

8. In a floor surfacing machine, the combination of, a frame having aforwardly disposed rotatable drum normally sustained above a surface tobe treated, intermediately disposed guide wheels each swingablyconnected to a side of said frame, spring means for holding said guidewheels continuously in contact with said surface, a trailing wheelhaving a swivel connection with said frame, a connection for elevatingthe rear end of said frame relatively to said trailing wheel to tiltsaid frame about said guide wheels and dispose said drum against saidsurface, rotatable regulating means cooperating with the last namedconnection for adjusting the pressure of said drum against said surface,and other regulating means for controlling said last named connection tobodily displace said frame relative to said trailing wheel.

9. In a floor surfacing machine, the combination of, a frame having aforwardly disposed rotatable drum normally sustained above a surface tobe treated, spaced guide wheels, spring actuated means rotatablysupporting said guide wheels and pivotally connected to the sides ofsaid frame for yieldingly holding said guide wheels in contact with saidsurface, a trailer wheel, adjustable means for bodily tilting said frameabout said guide wheels to dispose said drum against said surface andconcomitantly elevate the rear portion of said frame relative to saidtrailer wheel, and other independent regulating means for controllingthe elevation of said rear portion.

10. In a floor surfacing machine, the combination of, a frame having adrum normally disposed above a surface to be treated, guide wheels eachswingably carried by a side of said frame, spring means continuously andindependently holding said guide wheels in rolling contact with saidsurface, a rear trailing wheel continuously in rolling contact with saidsurface, a dust duct disposed Vwithin said frame, a fan associated withsaid duct, driving means carried by said frame and disposedsubstantially in alinement with said guide wheels andfoperativelyconnected to said Idrum and fan, and means carried by said frame tobodily tilt the latter relative to said trailing wheel about said guidewheels to differentially shift said drum towards or away from saidsurface.

11. In a floor surfacing machine, the combination of, a frame having adrum normally disposed above a surface to be treated, guide wheelsswingably carried by the sides of said frame, spring means forindependently holding each of said guide wheels in continuous rollingcontact with said surface, a rear trailing wheel continuously in rollingcontact with said surface, a dust duct disposed within said frame, a fanassociated with said duct, driving means carried by said frame anddisposed in alinement with said guide wheels and operatively connectedto said drum and fan, means carried by said frame to bodily tilt thelater relative to said trailing wheel about said guide wheels to shiftsaid drum towards o1' away from said surface, a handle carried to saidframe, and means controlled adjacent said handle for bodily tilting saidframe relative to said trailing wheel.

l2. In a surfacing machine, the combination of, a frame having arotatable drum normally above a surface to be treated, guide wheelsswingably carried by the sides of said frame, spring means forindependently holding each of said guide wheels continuously in rollingcontact with said surface, a trailing wheel continuously in rollingcontact with said surface and supporting the load of the rear end ofsaid frame, a fan, means carried by said frame for driving said drum andfan, and adjustable regulating means carried by said frame for bodilyshifting the latter relative to said trailing wheel and about said guidewheels to differentially dispose said drum towards and away from saidsurface.

13. In a surfacing machine, the combination of, a frame having arotatable drum normally above a surface to be conditioned thereby, atrailing wheel having means slidably supporting a rear portion of saidframe, an arm pivoted to each side of said frame, a guide wheelrotatably carried by each arm, spring means associated with each arm tohold the wheel thereof in yielding and pressural contact with saidsurface, means for adjusting the height of the rear portion of the framerelative to said trailing wheel, means for regulating the pressure oneach of said guide wheels, means to limit retraction of each of thelatter, and a handle for guiding said machine.

14. In a surfacing machine, a frame having a rotatable drum adapted tobe disposed in contact with a surface to be treated, intermediatelydisposed guide wheels, means swingaloly connecting said guide Wheels tosaid frame, spring means cooperating with said swingable means forcontinuously holding said guide wheels in rolling contact with saidsurface, a rear trailing wheel for supporting a part of the load of saidmachine and continuously in rolling contact with said surface, meansoverhanging the rear part of said frame for guiding displacement of therear portion of said frame relative to said trailing wheel, drivingmeans for said drum, and regulating means for displacing the rear partof said frame relative to said trailing wheel to tilt said frame aboutsaid guide wheels for adjusting the pressure between said drum andsurface.

